/** 
 * lsyncd.h   Live (Mirror) Syncing Demon
 *
 * License: GPLv2 (see COPYING) or any later version
 *
 * Authors: Axel Kittenberger <axkibe@gmail.com>
 *
 * Interface between the core modules.
 */

#ifndef LSYNCD_H
#define LSYNCD_H

/* includes needed for headerfile */
#include "config.h"

#include <signal.h>
#include <stdbool.h>
#include <stdlib.h>

#define LUA_USE_APICHECK 1
#include <lua.h>

/*-----------------------------------------------------------------------------
 * Lsyncd runtime configuration
 */
extern struct settings {
	/* If not NULL Lsyncd logs into this file. */
	char * log_file;

	/* If true Lsyncd sends log messages to syslog */
	bool log_syslog;

	/* -1 logs everything, 0 normal mode, LOG_ERROR errors only.*/
	int log_level;

	/* True if Lsyncd shall not daemonize. */
	bool nodaemon;	
	
	/* If not NULL Lsyncd writes its pid into this file. */
	char * pidfile;

} settings;

/*-----------------------------------------------------------------------------
 * time comparisons - wrap around safe 
 */
#define time_after(a,b)         ((long)(b) - (long)(a) < 0)
#define time_before(a,b)        time_after(b,a)
#define time_after_eq(a,b)      ((long)(a) - (long)(b) >= 0)
#define time_before_eq(a,b)     time_after_eq(b,a)

/* returns (on Lua stack) the current kernels * clock state (jiffies) */
extern int l_now(lua_State *L);

/* pushes a runner function and the runner error handler onto Lua stack */
extern void load_runner_func(lua_State *L, const char *name);

/* set to 1 on hup signal or term signal */
extern volatile sig_atomic_t hup;
extern volatile sig_atomic_t term;

/*-----------------------------------------------------------------------------
 * wrappers for heap management, they exit if out-of-memory. 
 */

extern void * s_calloc(size_t nmemb, size_t size);
extern void * s_malloc(size_t size);
extern void * s_realloc(void *ptr, size_t size);
extern char * s_strdup(const char *src);


/*-----------------------------------------------------------------------------
 * Logging
 */

/* Returns the positive priority if name is configured to be logged, or -1 */
extern int check_logcat(const char *name);

/* logs a string */
#define logstring(cat, message) \
	{int p; if ((p = check_logcat(cat)) >= settings.log_level) \
	{logstring0(p, cat, message);}}
extern void logstring0(int priority, const char *cat, const char *message);

/* logs a formated string */
#define printlogf(L, cat, ...) \
	{int p; if ((p = check_logcat(cat)) >= settings.log_level)  \
	{printlogf0(L, p, cat, __VA_ARGS__);}}
extern void
printlogf0(lua_State *L, 
          int priority, 
		  const char *cat,
		  const char *fmt, 
		  ...)
	__attribute__((format(printf, 4, 5)));

/*-----------------------------------------------------------------------------
 * File-descriptor helpers
 */
  
/* Sets the non-blocking flag for a file descriptor. */
extern void non_block_fd(int fd);

/* Sets the close-on-exit flag for a file descriptor. */
extern void close_exec_fd(int fd);


/**
 * An observance to be called when a file descritor becomes
 * read-ready or write-ready.
 */
struct observance {
	/* The file descriptor to observe. */
	int fd;

	/* Function to call when read becomes ready. */
	void (*ready)(lua_State *, struct observance *);
	
	/* Function to call when write becomes ready.  */
	void (*writey)(lua_State *, struct observance *);
	
	/* Function to call to clean up */
	void (*tidy)(struct observance *);

	/* Extra tokens to pass to the functions- */
	void *extra;
};

/* makes the core observe a file descriptor */
extern void observe_fd(
	int fd, 
	void (*ready) (lua_State *, struct observance *), 
	void (*writey)(lua_State *, struct observance *), 
	void (*tidy)  (struct observance *), 
	void *extra
);

/* stops the core to observe a file descriptor */
extern void nonobserve_fd(int fd);

/*-----------------------------------------------------------------------------
 * inotify
 */
#ifdef LSYNCD_WITH_INOTIFY
extern void register_inotify(lua_State *L);
extern void open_inotify(lua_State *L);
#endif

/*-----------------------------------------------------------------------------
 * fanotify
 */
#ifdef LSYNCD_WITH_FANOTIFY
extern void register_fanotify(lua_State *L);
extern void open_fanotify(lua_State *L);
#endif

/*-----------------------------------------------------------------------------
 * /dev/fsevents
 */
#ifdef LSYNCD_WITH_FSEVENTS
extern void open_fsevents(lua_State *L);
#endif


#endif
